Conventionally, a medical institution such as a hospital is equipped with an operating room and a treatment room, and a surgical light for irradiating an affected part at the time of performing a treatment on a patient is installed in these rooms. The surgical light has a structure that irradiates the affected part with high illuminance light, and a halogen lamp, etc. has been used as a light source. Besides, recently, a light emitting diode (LED) light source using an LED has been used as the light source. In this case, according to the IEC standard (IEC 60601-2-41) on illuminators for medical use, regarding a light field diameter and illuminance, it is necessary that a maximum illuminance value is 40000 LUX or more, and an illuminance value of 50% or more of the maximum illuminance value is ensured within a range of 50% from a center of an effective light field diameter (marked in a catalog, etc. of a product).
However, the above-described indoor installation type surgical light is high priced, and such surgical light equipment may not be installed depending on the medical institution. In addition, in the event of emergency such as disaster, conflict, etc., when emergency action is taken on a patient, the patient may not be urgently transported to a medical institution having the surgical light equipment or a treatment room in which the surgical light equipment is installed.
Therefore, in order to solve such a problem, Patent Document 1 discloses a head-mounted type lighting device which can be worn on a head of a medical staff to irradiate the affected part. The lighting device disclosed in Patent Document 1 incorporates a light-emitting unit that can ensure illuminance equivalent to that of the surgical light installed in the operating room, etc. and can be utilized in an emergency, etc.
Specifically, the head-mounted type lighting device disclosed in Patent Document 1 (hereinafter also referred to as a lighting device) includes a headband attached over a whole circumference of the head of the medical staff and a support band fixed to the headband and arranged to cross a top region of the head of the medical staff. These bands are adjustable in a lengthwise direction and configured to be attachable to different sizes of heads. A light-emitting unit incorporating a mounting board on which a large number of LEDs (LED light sources) are mounted is attached to a forehead region of the headband, and a support member through which the headband is inserted is provided in the light-emitting unit. In this case, the light-emitting unit is supported to be rotatable in a vertical direction through a spindle with respect to the support member, and an irradiation angle of light emitted from the LED light source may be adjusted when the light-emitting unit is gripped and rotated in the vertical direction. In addition, the LED light source incorporated in the light-emitting unit is configured such that illuminance of an irradiated part is 30,000 to 60,000 LUX even when the LED light source is 600 mm away from a front surface of the light-emitting unit. Further, even when the LED light source is used in the head-mounted type lighting device, irradiation light having high illumination may be obtained.